Download the theme from ThemeForest Download and unzip it on your computer. If you dont know how to do that you can refer to this link
Following items inside:- documentation: theme manual folder
- theme-package: contains the theme's installation zip files
- file-upload: contains file with links to images, video is used in our demo.
- arenafont: contains icon font arenafont and detail
- pre-setting: contains the sample data file settings-data.json as our demo. In the case of many styles (child-theme), this folder contains samples data according to the styles that you can install.
From your Shopify admin, go to Online Store > Themes.
In the More themes area, click Upload theme.
From the Upload theme window, click Choose File to select the .zip file that you want to upload.
Your new theme will show up below your current theme. It is installed, but not published. When you're ready to unveil your new look to the world, click Publish theme.